During the image forming process, toner is transferred from toner carrying members to print or copy media. Inefficiencies in the transfer process cause residual toner to remain on the toner carrying members or other transport members, such as transport belts, intermediate transfer belts/drums, and photoconductive members. Residual toner may also be created during registration, color calibration, paper jams, and over-print situations. This residual toner should be cleaned before it affects the quality of subsequent images. The residual or waste toner is commonly removed by a blade or other means and the removed toner is stored in a waste toner housing.
The effectiveness of a waste toner cleaner can be limited by back-pressure exerted at the cleaner throat by waste toner that accumulates in the housing. The cleaner throat is the area between a waste toner cleaner blade, a waste toner cleaner seal, and the surface being cleaned by the blade. Toner that is removed by the blade enters a waste toner cleaner housing at the throat. Back-pressure in this throat area may be generated by the sheer weight of the accumulated toner and may also be imparted through the accumulated toner pile by other devices in the housing, such as an auger that operates to move the waste toner to a location away from the cleaner blade. In any case, back pressure at the entrance to the housing can compromise the effectiveness of the cleaner by preventing newly cleaned waste toner from flowing into the cleaner housing.